在PostgreSQL中,有Limit和Offset关键字,可以非常容易地对结果集进行分页。

SQL Server的等效语法是什么?


当前回答

LIMIT的等效函数是SET ROWCOUNT,但是如果你想要通用的分页,最好这样写一个查询:

;WITH Results_CTE AS
(
    SELECT
        Col1, Col2, ...,
        ROW_NUMBER() OVER (ORDER BY SortCol1, SortCol2, ...) AS RowNum
    FROM Table
    WHERE <whatever>
)
SELECT *
FROM Results_CTE
WHERE RowNum >= @Offset
AND RowNum < @Offset + @Limit

这里的优点是,如果您决定更改分页选项(或允许用户这样做),则可以将偏移量和限制参数化。

注意:@Offset参数应该使用基于1的索引,而不是普通的基于0的索引。

其他回答

select top {LIMIT HERE} * from (
      select *, ROW_NUMBER() over (order by {ORDER FIELD}) as r_n_n 
      from {YOUR TABLES} where {OTHER OPTIONAL FILTERS}
) xx where r_n_n >={OFFSET HERE}

注意: 这个解决方案只能在SQL Server 2005或更高版本中工作,因为这是实现ROW_NUMBER()的时候。

另一个例子:

declare @limit int 
declare @offset int 
set @offset = 2;
set @limit = 20;
declare @count int
declare @idxini int 
declare @idxfim int 
select @idxfim = @offset * @limit
select @idxini = @idxfim - (@limit-1);
WITH paging AS
    (
        SELECT 
             ROW_NUMBER() OVER (order by object_id) AS rowid, *
        FROM 
            sys.objects 
    )
select *
    from 
        (select COUNT(1) as rowqtd from paging) qtd, 
            paging 
    where 
        rowid between @idxini and @idxfim
    order by 
        rowid;

因为,我测试了更多次这个脚本更有用的100万条记录,每页100条记录分页工作更快,我的PC执行这个脚本0秒,而与mysql相比有自己的限制和偏移约4.5秒得到结果。

有些人可能不理解Row_Number()总是按特定字段排序。如果我们只需要按顺序定义行,应该使用:

Row_number () over (order by (select null))

SELECT TOP {LIMIT} * FROM (
      SELECT TOP {LIMIT} + {OFFSET} ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) AS ROW_NO,*
      FROM  {TABLE_NAME}
) XX WHERE ROW_NO > {OFFSET}

解释:

{LIMIT}:每页的记录数 {OFFSET}:跳过记录的个数

我假设,在c#表达式/LINQ语句的跳过和采取生成下面的SQL命令

DECLARE @p0 Int = 1
DECLARE @p1 Int = 3
SELECT [t1].[Id]
FROM (
    SELECT ROW_NUMBER() OVER (ORDER BY [t0].[Id]
    FROM [ShoppingCart] AS [t0]
    ) AS [t1]
WHERE [t1].[ROW_NUMBER] BETWEEN @p0 + 1 AND @p0 + @p1
ORDER BY [t1].[ROW_NUMBER]

您可以在公共表表达式中使用ROW_NUMBER来实现这一点。

;WITH My_CTE AS
(
     SELECT
          col1,
          col2,
          ROW_NUMBER() OVER(ORDER BY col1) AS row_number
     FROM
          My_Table
     WHERE
          <<<whatever>>>
)
SELECT
     col1,
     col2
FROM
     My_CTE
WHERE
     row_number BETWEEN @start_row AND @end_row